Twilight Frontier (黄昏フロンティア Tasogare Frontier, or Tasofro for short) is a Japanese doujin game developer. They are noted for making high quality derivative works of other games.
- Eternal Fighter Zero - A 2D fighter based on One: Kagayaku Kisetsu e, Moon., Kanon, and Air. Later editions include:
- Eternal Fighter Zero -RENEWAL-
- Eternal Fighter Zero: Blue Sky Edition
- Eternal Fighter Zero: Bad Moon Edition
- Eternal Fighter Zero -Memorial-
- Immaterial and Missing Power - A 2D fighter that is part of the Touhou Project; a collaboration with Team Shanghai Alice.
- Gensōkyoku Bassui (幻想曲抜萃 Collection of Illusionary Music) - The OST for the game.
- MarisaLa (スーパーマリサランド, "Super Marisa Land") - A platformer that is a parody of both Super Mario Land and Touhou.
- MegaMari (メガマリ -魔理沙の野望-) - An action game parodying Touhou with Mega Man. Released on May 2006.
- Higurashi Daybreak - A 3D third-person shooter based on Higurashi no Naku Koro ni co-authored by 07th Expansion.
- Defend the library! (ぱちゅコン！, "Patchucon!") - A real time strategy game based on Touhou, released on December 31, 2007.
- Scarlet Weather Rhapsody (東方緋想天) - A versus fighting game similar to Immaterial and Missing Power, part of the official Touhou Project series as well, numbered 10.5. It was up for beta testing during the 2007 Reitaisai.. Released at Reitaisai 5 on May 25, 2008.
- Zenjinrui no Tenrakuroku (全人類ノ天楽録 Celestial Music Record of All Humankind) - The OST for the game.
- Touhou Hisoutensoku - It is numbered 12.3 in the series and introduces new spell cards and weather conditions. Characters from Scarlet Weather Rhapsody can be played in versus mode if that game is installed.
- Kakunetsu Zoushin Hisoutensoku (核熱造神ヒソウテンソク "Thermonuclear Deity Hisoutensoku") - OST for the game, released in 2009.
- New Super Marisa Land (魔理沙と６つのキノコ, "Marisa and the Six Mushrooms") - A more sophisticated successor of MarisaLa, released in 2010.
- Natsu no Kagerō (なつのかげろう) - a 3D game collaboration with Ryukishi07 of 07th Expansion.
- 海原いるか (Umihara Iruka) — General Producer/Character Graphics/System Graphics/Script/Sound Effects
- ののたろう (Nono Tarō) — Chief Programmer
- KuMa — Assistant Programmer
- alphes — Character Graphics
- スペクター (Specter) — Character Graphics
- 長谷川イワシ (Hasegawa Iwashi) — Character Graphics/Background Graphics
- GOME — Character Graphics
- JUN — Sound Effects
- NKZ — Music